


What Is Truth

by 1StarShine1



Series: What Is Truth [1]
Category: Undertale (Video Game)
Genre: Crossing Dimension, F/M, The Characters May Never Know, They Think It's Just A Dream, What's The Truth, You Think It's Not
Language: English
Status: Completed
Published: 2019-07-16
Updated: 2019-07-20
Packaged: 2020-06-29 15:59:47
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 2,976
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19833577
Author URL: https://archiveofourown.org/users/1StarShine1/pseuds/1StarShine1
Summary: You had fallen in the Underground some time ago, but you were ok. You made friends with most of the monsters that were trapped there with you. Yes, real monsters. All of the sudden you were having dreams where you were waking up in a hospital on the surface. Everything that was going on there was making you question reality.





	1. Chapter 1

**Author's Note:**

> [This](https://archiveofourown.org/works/14673180/chapters/33899853) was the thing I was reading when I got this idea.

Falling down the hole in the mountain had to have been the best stupid clumsy move you've ever made. Sure it was terrifying at first; You feared you were going to starve and rot at the bottom of the pit, but then your fears shifted when you realized you weren't alone down here, and this place is a lot bigger than you thought.

It was like you walked into a fairy tale as you learned you were in the land of monsters. Beings, you learned, that were cast underground in fear that they were trying to become all-powerful against humans. Now you didn't believe that one bit. Most of your interactions were downright pleasant. A very kind goat lady named Toriel was nice enough to let you stay in her humble little home.

You stayed with her for about a week until you got this itch for adventure. It took some time, but you were able to convince her that you'd be absolutely fine if you passed the Ruins' door. That's when you met _him_.

Sans The Skeleton. He did not like you one bit. You could see it in those sharp pinprick eye-lights, past the jokes whoopie cushions, and puns. It was completely understandable. Who would trust a stranger, monster or not, they've never seen before. At least he gave you a chance, which you're grateful for.

That chance blossomed into a loving, strong relationship. Here you were almost two years in the Underground you found a motherly figure in Toriel, you've made friends with so many monsters, and you had a boyfriend. The only fear you had is running into Flowey, the demonic flower that tried to kill you in your very first encounter. All this time, though, you hadn't seen stem nor leaf of him since.

You weren't just sitting around doing nothing all the time, though. You were working with Alphys, the yellow dinosaur monster and Royal Scientist, to bring down that barrier trapping everyone. Today was one of those days...mostly. You got what work you could do done by late afternoon, and spent the rest of the evening watching anime. It was Sans that pulled you away like some kid not wanting to leave their friend's house after a sleepover. You even gave a petulant whine to which he only chuckled, kissed you on the forehead, and guided you through his magic shortcut to his and his brother's, Papyrus, place.

When night fell and it was time for bed you listened in on Sans reading his brother a bedtime story (which gets cuter every time). Then you curled up with Sans in your shared bed, hands intertwined you fell asleep together in a loving warmth.


	2. Chapter 2

You woke up to the distinct smell of...clean is the only way you could describe it, and bright white lights even before you opened your eyes. At first, you thought you never went back to the skelebro's house, and just fell asleep with Alphys and Undyne, but even with Alphys's place being a lab it's wasn't this clean.

When your eyes adjusted to the brightness you cracked them open and kept blinking until you could open them fully. You were frozen in fear when you realized this isn't a place you knew at all. It was a hospital room, and you looked to be the patient since you were in a hospital gown and had an IV line in your arm. You looked wide-eyed out the window and saw a huge oak tree taking up most of the view, but the rest of it, and even through the leaves you saw a bright blue sky and rays of sun shining in. What are you doing on the surface? What's going on here?!

The door opened, and your eyes instantly snap to a person you haven't seen in literal years. “Mom?”

She had her hair pulled back tightly, she wore her casual clothes and had a briefcase. Her head snapped up at hearing your voice, and she was by your side in an instant hugging you close. Thankfully she was on the opposite side of the IV so you could dumbly hug her back.

“I'm so glad you're awake.” She was so chocked up. “Let me page a doctor so they can explain everything. I'm sure you're rightly confused.”

She pressed the call button attached to your bed, and a young-looking male nurse hurried in. His smile brightened when he noticed you were cognitive and immediately said about getting the doctor. The doctor came in shortly after and she was a young, sprightly looking thing yet her eyes portrayed years of experience.

“Hello (Y/N). It's great to see you fully awake.” She greeted. “How are you feeling right now?”

“...Like I was having a good night sleep, and someone tried to wake me up by shining a flashlight in my face. My head kinda hurts from the initial brightness of everything.” You say.

"We can get you something for that if you want after we finish here. What's the last thing you remember?"

Since you were still utterly confused as to why you're here you figured it might not be the best idea to talk about the Underground. “I went hiking up Mt. Ebott, but my question is how long ago was that.” Usually when a doctor asks what you remember the patient either had head trauma or were in a coma.

“That was almost two years ago honey.” Your mom gently informs.

Your eyes bug out at that and you squeak, “Huh?”

The doctor kindly and professionally explained everything. "It started with your return home from hiking. You had complained about not feeling well, and one day you didn't wake up at all. You were brought here to be treated. We did find and treat an infection, we ruled out Lyme Disease because there was a tick on your lower calf, and we believe we know what is ailing you now.

You possibly have Kleine-Levin Syndrome also known as Sleeping Beauty Syndrome. It explains the hypersomnia, or excessive sleeping/sleepiness, and the changes in mood and awareness.”

There's only one thing. “I didn't come down from the mountain. I couldn't have. I...” You were hesitant to talk about the Underground, unsure of _any_ thing and what ramifications there could be if you speak.

“Well, where did you end up since you say you didn't get home?” The doctor prompted.

“You're going to think I'm crazy if I say.” You whisper.

“Honey you're not in a place to be judged, but to get better. We just want to help.”

Your mom was softly rubbing your back. With her ministrations, you couldn't focus and started to feel tired. You couldn't fight the calls of slumber.


	3. Chapter 3

You jolt slightly when you awaken, but quickly relax when Sans's dark messy room comes into focus. You carefully maneuvered out from under your loverbone. You sat on the edge of the bed for the moment and picked up a dirty shirt that was discarded to the floor who knows how long ago. You could _feel_ the raised pattern as you wrung it. You slowly raked your gaze across the clutter. You could feel the carpet between your toes, the chill in the air from the snowy landscape, and smell the mix of a snowy pine forest and old books that reminded you of Sans. How can this be all a fabrication if everything felt so real?

You jolt from your thoughts when Sans silently placed a hand on your shoulder. You barrel into him, nearly knocking you both over, but he stood strong. He tried to ask what was wrong, but you were too overwhelmed and on your way to an anxiety attack. He wraps you in a bear hug and backs up until his legs hit the bed. He situated you both so you're curled up with your head in the crook of his neck, and he was curled protectively around you, phalanges carding through your hair trying to help you calm down.

It took you an embarrassingly long moment to regain control. He tried asking again and through your tears you whisper, "I don't know if this is real." You take a stuttering breath.

“What?” He asks completely confused as he tried to fight down a yawn.

"I was having this dream where I woke up in a hospital I'd apparently been in for two years with some kind of rare disease. With the way the conversation was heading, they were probably trying to convince me that all of this" You gestured around the room. "is just a dream."

“When did all this start?” He didn't immediately dismiss this. Your heart unclenched with a spark of hope that he can help figure this out.

“Just right now, but I was so scared. I could feel just as much as I could here. I could smell the hospital chemicals, could feel it when my mother squeezed me in a hug. There was such emotion, such life, in that room. It just felt so _real_ I don't know what to believe.”

Your hands were shaking again as one skeletal hand firmly grasped them, and the other guided your chin to look your skeleton boyfriend in the eye-sockets. Looking in his strong, sturdy eye-lights helped you break from your panic and fully relax. Sans placed a loving kiss on your forehead as you both got situated back in bed. You faced one another one hand interlaced.

“Don't worry we'll figure this out in the morning. No _bones_ about it.”

You huff at that. He loves his puns and they never fail to get a reaction from you. He's always there to make someone laugh. He's always so supportive and caring.

_Too good to be true_.


	4. Chapter 4

You don't know how to feel when you woke up to the familiar clutter that was Sans's room, and alone at that. You sat on the edge of the bed rubbing the sleep from your face and crust from your eyes. Sans came back a short time later with a heavenly smelling plate of something.

“Wakey, wakey eggs and bakey.” He said handing you the plate that had some scrambled eggs, two pieces of perfectly crispy bacon, and a slice of buttered toast cut diagonally. As you chowed down he continued. "I was wondering if you had any plans for the day."

Well considering that most of your plans involve hanging out with him, “Don't think so.” You go back to nibbling on the toast.

He looked pleased and then just tossed a box in the air for no reason. You had to catch it before it landed in your eggs. It's a box of raisins. You tossed them back informing him you don't like raisins.

“That's OK, how 'bout a date.” It took you a moment to register what the bonehead said. That was so corny, so out there, but just so him.

When you finished you fluttered your eyelashes in an attempt to get Sans to take the plate downstairs. That look never fails to get him to do what you want. _Just like you'd imagine_. You changed from your PJs and joined him downstairs. Seeing Papyrus gone you figure he's out on patrol already.

“So what do you have in store for me today Bones?”

You were both walking arm in arm through a deeper part of Waterfall. Unfortunately, there's not much more you could do being trapped in this place. Which was something you were still arguing with yourself about. Why would you imagine somewhere where you're trapped. If that's not some twisted allegory for you literally being trapped in your mind.

You need to put this aside for now and enjoy the sights. The near pitch darkness only lit by the low, lightly pulsing glow of gems in the stone wall. The distant sound of falling rain follows you making it feel so peaceful. You let him guide you as you lean your head on his shoulder and close your eyes, immersing further in the atmosphere.

“Keep your eyes closed until I say. There's something I wanna show you.” Sans whispered.

You trailed behind him, still holding his hand, for a little while longer. Then he had you sit when you got to the top of a hill. When he told you to open your eyes your jaw would have dropped to the ground if you were a skeleton. Your eyes had long since gotten used to the darkness of Waterfall, and that just made it all the more breathtaking. You were on top of a steep cliff side with a chasm below that had an entire city nestled in it. On the ceiling above it were hundreds of the star-like crystals that you could find in the wishing room.

You were there for a while admiring the beauty of it all. When Sans stood you figured he wanted to go elsewhere, but he kept standing there both hands holding yours. He was holding you in place because he had something to tell you. In your experience, that phrase is usually followed by bad news. He was blushing his pretty blue color, though.

“Would you want to bond with me?”

The world stopped for a moment. He was asking you to bond?! You only know what that entails because you semi-forced to read into it (though you had been curious about customs too) by the hopeless romantic, Alphys. She always somewhat loved playing matchmaker.

“Is that even possible between human and monster?”

“Any two Souls can find love, they are the _heart_ of the matter.”

Your nose starts tingling as you try to keep emotions in check. Your voice was failing you so you hoped your actions could convey the magnitude of your conviction. He pulled you closer and whispered to hold tight as he teleported you both to your shared room.


	5. Chapter 5

Whatever doubt you had was gone. The emotion, the memories shared, the raw energy, how can this be a fabrication? You saw, and felt, things from his childhood that you've never heard him speak of, and for good reason. The overwhelming fear of not knowing what new horrible thing is going to happen to him as he's dragged from this cell, for example.

You felt this wholeness since bonding with Sans, and that made you happy. You were laying in bed together, limbs entangled, enjoying the moment. One thing to come out of this is you now have a little magic of your own.

"It's not much. at most you'll be able to sense the use of magic clearer, and you can pull out your soul."

He's right. You can feel this unexplained calm hum in the air. You snuggled into his chest as he pulled the soft quilt over you both, and fell asleep together.

The clean smell hit you first when you, and you had to squint until you were adjusted to the florescent lights above. No! You thought you were done with all of this. Why were you back here again? It's fine you can prove once and for all that this is the dream, an idealistic wish to be on the surface again and see your parents. The dream would fade, then you could get back to work with Alphys and actually make it back to the surface.

You pressed the call button and a nurse came in asking if I needed anything. You responded with, “Someone that knows what's going on.”

Your mother came in a few minutes later and the nurse said the doc would be in shortly. She gave you a crushing hug in greeting, and when the doctor arrived you basically tried to pick up where you left off. You were still somewhat convinced they thought you were crazy, but you told everything. They both were still trying to say it was just made up by your mind, but you weren't having it.

“I have proof.” Souls may be a private matter, but if it got them to listen then so be it. You tried to reach inward for that spark of life and pull it forward, but there was nothing there. You couldn't feel your soul! That was enough to send you in a little panic.

"Honey, it's all right." Your mom tried to comfort you, but you moved away from her attempts.

The doctor steamrolled right past this. "We need to break this cycle. I think that in this situation you need to try and make this Underground an unappealing place to be in." How were you supposed to do that? "What do you like most about the place?"

There were a few things that came to mind, but the top would have to be, “The people.” You had a bad feeling after you said that.

"Wouldn't it be a wise decision to kill all those there so as not to have a reason to be there?" You just stared wide-eyed at the doctor.

“Are you telling me to murder innocent people?!” You screech. “NO! Real or not I have morals!” You didn't want to hear any more of this. You slammed your head into the pillow, plugged your ears, and closed your eyes tight.

Petty? Probably. Ineffectual. Most definitely, but the nerve to even suggest something like that.

~Across Dimensions~

There was a breakthrough in the lab. The human and the royal scientist found the way to break the barrier without any lives being taken. All it needed was a little time and the energy and they could be free.

On the other side a girl has slipped into, what doctors think is, a coma. Slowly but surely they're seeing less and less activity of all functions. The girl fades away in one world as she's about to greet the surface and the new adventures to come.

**Author's Note:**

>   
>  Totally didn't forget that today was my birthday. Only saw it when I looked to see when I posted this. >.>   
> 


End file.
